1. Field of the Invention
The present invention relates to a carbon nanotube apparatus for surface discharge polishing, and more particularly to a transistor discharge circuit which can precisely control the energy in electrical discharge machining to achieve nanometer-level micro machining.
2. Description of the Prior Art
Since the introduction of carbon nanotube in the early 1990, there's been tremendous research enthusiasm regarding to this new material in its structure and its mechanical, thermal and electrical properties. According to various computer simulation analyses or experiments on single-wall carbon nanotubes (SWCNTs) or multi-wall carbon nanotubes (MWCNTs), it is well known that carbon nanotubes are of high rigidity, and are also good conductors of heat and electricity. Moreover, due to its high length-to-width ratio, it is viable to produce high electric field intensifying effect. Therefore, it is capable of providing electron field emission characteristics under low electric field.
At present, electrical discharge machining is based on the erosion mechanism of pulse discharge, wherein the tool and the target connected to two ends of pulse source respectively. Electrical discharge machining is different from electrochemical machining in that its electrode could be worn out, therefore careful selection of abrasion-resistive electrode material, proper electrode size and parameters of electrical discharge machining could reduce the worn-out effect on the precision of discharge machining.
However, recently there's been great improvements on micro electrical discharge machining, where researchers use etching or wire electric discharge guide on thin rod of 2 μm in diameter to manufacture tungsten electrode. The precision of discharge machining is then to be controlled by the size of the pre-built tungsten electrode. Hence, it is a revolutionary and innovative way in implementing micro-mechanical machining technology.
Although mechanical machining is nothing more than the forming and surface treatment processes, it is noted that, for example, in the surface treatment process, the nickel plate used in modern hard disk should have an average roughness (RA) of 120 nm and a storage volume of 80 Gb through CNC machining. In order to obtain a storage volume of 160 Gb, the average roughness should reduce to 50˜70 mm, that is not viable under current techniques.
Therefore, the above-mentioned devices present several shortcomings to be overcome.
In view of the above-described deficiency of prior-art devices, after years of constant effort in research, the inventor of this invention has consequently developed and proposed a carbon nanotube apparatus for surface discharge polishing to achieve nanometer-level micro machining.